1. Field of the Invention
The present invention relates to a new method and apparatus for providing a reconfigurable well-logging data acquisition and interpretation system that provides a lower-cost, higher reliability data acquisition and interpretation system than previously available while retaining redundant response to component failure.
2. Background
Well-logging systems today typically use sophisticated on-site computer systems for acquiring and interpreting well-logging data from a down-hole logging tool. Such systems are typically operated in harsh environments, far from suitable repair locations. System failures in a well-logging operation create expensive and unacceptable down-time. Thus, a high degree of system reliability is an essential attribute for such systems.
Historically, a high degree of system reliability has been attained through total hardware redundancy with little or no use of the redundant hardware until a failure occurs. Failure recovery mechanisms for such redundant systems basically consist of two complete compliments of the hardware required to perform the particular function of the system. When the primary system fails, it is totally replaced by the back-up system. Back-up or redundant systems, of course, add significantly to the cost of the system. Secondly, well-logging systems must be transported to the well site and are typically mounted in trucks or other transport means where adequate space is usually lacking. Back-up or redundant systems occupy valuable space which could be put to better use.
One possible solution is simply providing a box of spare hardware components and parts for the primary system based upon historical failure rate data for individual components required in the system. That could possibly meet the availability requirement at lower cost figures for acquisition and space requirements, but the time required to diagnose which component had failed, and to physically remove it and replace it is too long.
The present invention arose from the realization that a spare set of components might not be necessary if the required processing could be redistributed across the remaining, operational elements in the system in the event of a failure of one or more individual components. The inventors have determined that it is possible and practical to switch the failed element or elements out of the system and redistribute the processing task to complete the particular function the system was intended to perform That provides a lower-cost, highly reliable, adaptable system.